Here's a thread I stole from Spongey over at AGS. Okay, so basically you have to say something nice about the guy/girl who posted before you. And it has to be honest. You can't lie or be sarcastic. If you don't like the person, try finding some part of their personality that you value.

alien did not eat my brain yet, which i find very friendly of him. he is always anxious not to drip with his slimy icky spit onto the carpet or the couch.
also i'd like to point out that he always got a wall at hand if you need one.. good boy, alien!!!